1. Field of the Invention
The present invention related to a solid state relay with an optical isolator assembly and specifically to such a relay with circuitry for detecting overload conditions to protect the relay in the event the relay is switched on into a shorted load, or if a short is switched across the load while the relay is on.
2. Description of the Prior Art
Optical isolators are known in the art for use either as a discrete component, connected in a circuit with other components, or integrated in a chip with other components as a unit. Such isolators are used, for example, in combination with Darlington drive circuits, triac driver circuits, Schmitt trigger circuits, and various types of logic gate circuits.
Solid state relays, with and without an optical isolator, are also known in the art. A problem in the use of such relays is their susceptibility to damage under overload conditions, such as if the relay is switched on into a shorted load, or if a short is switched across the load while the relay is on.